1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef _LIBCPP___ALGORITHM_MERGE_H
10#define _LIBCPP___ALGORITHM_MERGE_H
11
12#include <__algorithm/comp.h>
13#include <__algorithm/comp_ref_type.h>
14#include <__algorithm/copy.h>
15#include <__config>
16
17#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18# pragma GCC system_header
19#endif
20
21_LIBCPP_BEGIN_NAMESPACE_STD
22
23template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
24_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator __merge(
25 _InputIterator1 __first1,
26 _InputIterator1 __last1,
27 _InputIterator2 __first2,
28 _InputIterator2 __last2,
29 _OutputIterator __result,
30 _Compare __comp) {
31 for (; __first1 != __last1; ++__result) {
32 if (__first2 == __last2)
33 return std::copy(__first1, __last1, __result);
34 if (__comp(*__first2, *__first1)) {
35 *__result = *__first2;
36 ++__first2;
37 } else {
38 *__result = *__first1;
39 ++__first1;
40 }
41 }
42 return std::copy(__first2, __last2, __result);
43}
44
45template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
46inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
47merge(_InputIterator1 __first1,
48 _InputIterator1 __last1,
49 _InputIterator2 __first2,
50 _InputIterator2 __last2,
51 _OutputIterator __result,
52 _Compare __comp) {
53 return std::__merge<__comp_ref_type<_Compare> >(__first1, __last1, __first2, __last2, __result, __comp);
54}
55
56template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
57inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
58merge(_InputIterator1 __first1,
59 _InputIterator1 __last1,
60 _InputIterator2 __first2,
61 _InputIterator2 __last2,
62 _OutputIterator __result) {
63 return std::merge(__first1, __last1, __first2, __last2, __result, __less<>());
64}
65
66_LIBCPP_END_NAMESPACE_STD
67
68#endif // _LIBCPP___ALGORITHM_MERGE_H
69